Discharge-valve gear for blowing-engines.



C. G. SPRADO.

DISCHARGE VALVE GEAR PoR BLOWING ENGINBS. APPLICATION FILED 1113.15,1911` 1,979,374.

Patented Nov. 25,1913.

WITNESEEE- EY i g%%%\ATTDRNEW COLUMBIA PLANUGRAPH Co. WASHlNn'rrkoN. D.c.

UNITED sTATEs PATENTI oEEioE.

CARL G. SPRADO, OF MILWAUKEE, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS,T0 ALLIS-CHALMERS MANUFACTURING COMPANY, A CORPORATION 0F DELAWARE.

DISCHARGE-VALVE GEAR FOR BLOWING-ENGINES.

To all whom t may concern Be it known that I, CARL G. SrnADo, a citizenof the United States, residing at Milwaukee, in the county of Milwaukeeandi State of Wisconsin, have invented a certainnew and usefulImprovement in Discharge- Valve Gears for Blowing-Engines, of which thefollowing is a specification.

This invention relates to improvements in the construction of valvegears for blowing engines, and more particularly to the construction ofdischarge valve gearssuch as may be used in combination with the Slick:type of inlet valve for such blowing engine.

The object of the invention is to provide a valve gear for the dischargevalves of blowing engines which is simple in construction, efficient inoperation, and` in which when the valve is seated, the kinetic energy ofthe gear is t-aken up by a stop and not by the valve seat.

A clear conception of one embodiment of the invention can be obtained byreferring to the accompanying drawing in which like reference charactersdesignate the. same or similar parts in the various views.

Figure 1 is a fragmentary central vertical section through a dischargevalve gear and a portion of the cylinder of a blowing engine having theSlick type ofinlet gear. Fig. 2 is an end view of the discharge valvegear shown in Fig. 1. Fig. 3 is a transverse vertical section throughthe valve gear, the sectio-n being taken along the line III-111 o-f Fig.1, looking toward the cylinder.

The discharge chamber 1 of the cylinder, see Fig. 1, is connected to theinterior or piston chamber of the cylinder by a port 6. The piston 5,which is of the usual construction, is adapted to reciprocate within thecylinder, thereby approaching and receding from the discharge port 6.The tub or cylinder wall 3 is adapted to be mechanically reciprocated sothat during the suction stroke of the blower the suction ports 4 formcommunicating passages between the suction chamber 2 and the interior ofthe cylinder.

The discharge valve bonnet 13, see Figs. 1, 2 and 3, is fixed to the endof the cylinder and has a spring casing 9 projecting inwardly therefromin a direction parallel to the cylinder aXis. The valve plunger rod 10,which is mounted concentrically within the bonnet 13 and spring casing9, carries a Specification of Iiettersatent.

Application filed February 15', 1911.

Patented Nov. 25, 1913.

Serial No. 608,689.

plunger 8 at its valve end, the plunger 8 coacting along the innercylindrical surface of the discharge cup valve 7. The sprin seat 11 isfixed to the plunger rod 10, an forms a seat for one end of thecompression `spring 12, the opposite end of said spring coacting againstan end surface of the bonnet 13.

The bonnet 13. is provided with guides or ways in which a crosshead 15is adapted to .reciprocate The crosshead 15, see Figs. 1, ,2 and 3, isprovided with two coaxial outwardly projecting ins 17. The plunger rod110 passes freely tirough the crosshead 15 and is adjustable within thecrosshead 15 by means of a squared portion 20 at its outer extremity anda nut 21 having screw thread Vcoaction with the outer end of the rod 10and coacting against an outer surface of the crosshead 15. A stop plate18, which is alsoy penetrated by the plunger rod 10, is securely fixedto the bonnet 13 by means of `bolts 19 or other suitable fastenings.

The rocker arms' 25 take over the outwardly projecting stud 17 formed onthe crosshead 15 and have upper cam surfaces `which ride upon thecam'tracks 14 formed on the bonnet 13. Adjacent rocker arms 25 farerigidly connected by means of a cross rod '22. The operating connection24, which is driven mechanically from the main engine shaft in anysuitable manner, not shown, is connected to the rocker arms 25 by meansof the pivot pin 23.

A suitable stuiiing boX 16 which may be of any of the well known forms,is provided to maintain a tight joint between the bonnet 13 and theplunger rod 10. In actual construction of the device, suitable oilingarrangements should also be provided at the various bearing surfaceswithin the cylinder head, these being omitted from the disclosure sincethey form no part of the present invention and would only tend tocomplicate the drawings.

During the discharge stroke of the piston, namely, toward the left inFig. 1, the pin 23 is raised, causing the rocker arms 25 to ride withtheir cam surfaces upon the adjacent cam tracks 14, mechanically drawingback the crosshead 15, and the plunger 8. This withdrawing of theplunger 8 is accomplished during the early part of the forward stroke sothat the valve is left free to open at any time as the pressure withinthe cylinder increases. The opening of the valve 7 occurs when thepressures within the cylinder and in the discharge chamber l becomeslightly unbalanced, the pressure within the cylinder being the greater.

When the piston 5 has reached the end of its stroke, the valve 7 shouldbe suddenly clo-sed. This closing of the valve 7 is accomplished firstby the forward pressure of the spring l2 on the plunger 8, and later bythe discharge pressure in the chamber l acting directly on the valve 7.With such arrangement the plunger 8 can force the valve 7 to nearly itsclosed position, or until the plunger, stem and crosshead are arrestedby stop 18, the forward motion of the plunger 8, however, being eitherrapid or slow, depending upo-n the force of the rush of air from thecylinder, thus permitting automatic closing of the valve. In otherwords, the plunger is spring actuated and mechanically restricted in theclosing direction up to a point where the over pressure inside of theblowing cylinder is equal to the spring pressure exerted on the plunger,and an automatic spring closing takes place from this point on at thetime when the main piston comes to a stop. It will be noted that aslight air space is shown existing between the plunger 8 and the valve7. The depth of this air space represents the distance through which thevalve 7 is actually forced by the high air pressure within the chamber lafter spring closing.

With the arrangement of plunger rod 10 as shown, namely, extendingthrough the crosshead 1,5, and having the adjusting means on the outerend thereof, it will be noted that the adjustment of the plunger 8 canbe easily and quickly made during normal operation of the blower.

It should be understood that it is not desired to be limited to theexact details of construction shown and described, for obviousmodifications will occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent,-

1. In a valve gear, a Valve, means for permitting opening of said valve,means for mechanically operating said opening permitting means in onedirection, means for automatically operating said opening permittingmeans in the opposite direction to move said valve toward closedposition, and a stop for said opening permitting means.

2. In a valve gear, a valve and seat therefor, a plunger contractiblewith said valve, means for withdrawing said plunger from Contact withsaid valve, impositivo means for urging said plunger in the oppositedirection, and a stop for said plunger to limit the action of saidimpositive means.

3. In combination, a valve, a plunger, means operating said plunger tomove said valve toward closing position, and a stop for said plunger.

In testimony whereof, I aiix my signature in the presence of twoWitnesses.

CARL G. SPRADO.

Witnesses:

CHAs. L. BYRON, W. II. LIEBER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

